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Corrosion under Insulation


Corrosion under Insulation (CUI) is a thread to the process industry in a wide sense.
If neglected, the corrosion process is mostly well hidden under the insulation system and becomes only obvious due to severe integrity failures.

Sample Corrosion under Insulation
Corrosion under insulation

Time for a comeback.

As the saying goes, if it isn’t broken, then why fix it? You could certainly say that this applies to the thermal spray coating process, which has been around since the 1930s. Nowadays, the focus is on ‘new’ and ‘modern’ technology. But just because a certain technology has been around for decades doesn’t mean that it isn’t useful.

Technology that works, works for a reason. And aluminium thermal spray coating is a proven, safe and efficient way to protect large surfaces that are exposed to extreme conditions. That’s why KAEFER still makes extensive use of this technology, but with modern application tools and processes.

Aluminium protects steel surfaces over a broad range of temperatures (from cryogenic to +538°C) and unlike zinc, aluminium does not undergo galvanic reversal at higher temperatures, which makes zinc unsuitable for CUI protection solutions.

Combining proven technology with KAEFER innovative thinking means we can make the most of the resources we have and make them useful for the future.


We have developed our own approaches to fight CUI, e.g. by an own coating system specification guideline, definition of best practise insulation system design to prevent water ingress in the system and to prevent CUI.